One interpretation of the medical caduces symbol} from 
antiquity is that it represents the lyre-shaped configuration 
of two snakes contesting one-another. Such a belief may have 
been derived from observing the combat ritual of Elaphe 
longissima which assumes a lyre-like posture during this type 
of interaction and is called the Aesculapian Snake after the 
God of Medicine. If this interpretation ls correct then: the 
presence of this combative behavior in snakes has been 
recognized since ancient times. 
However, it is not until the early part of this century 
that references to combat rituals in snakes began to appear in 
the scientific literature, and in recent years the list of 
references has grown to now include a breadth of species in 
the families Boidae, Colubridae, Elapidae and Viperidae 
(Viperinae and Crotalinae). 
It is the purpose of this inventory to bring together a 
list of the species of snakes for which, in my interpretation, 
the phenomenon of combat ritual has been authenticated via 
published literature sources. I also hope that this inventory 
will stimulate others to watch for this type of behavior, 
refer to some of the most recent descriptions for methods of 
observing and describing, and help to lengthen this list. In 
this way we will all contribute to grasping a better 
understanding of what snake combat rituals mean and how they 
may have evolved. 
